The whole point of using Delphi/C++Builder for mobile development is that you DO NOT have to code in Objective-C/Java, you code in Delphi/C++ like you normally would. However, you do need to understand that you are accessing iOS/Java native objects via an intermediate bridge into the iOS/Java worlds, so it would help to have a basic understanding of how iOS/Java actually work under the hood, or at least be able to read their documentation and understand how Embarcadero has mapped them into the Delphi/C++Builder world.